Signals and slots is a language construct introduced in Qt[1] for communication between objects which makes it easy to implement the observer pattern while avoiding boilerplate code. The concept is that GUI widgets, and other objects, can send signals containing event information which can be received by other objects using special member functions known as slots. This is similar to C/C++ function pointers, but the signal/slot system ensures the type-correctness of callback arguments.[citation needed]
The signal/slot system fits well with the way graphical user interfaces are designed.[citation needed] Similarly, the signal/slot system can be used for other non-GUI usages, for example asynchronous I/O (including sockets, pipes, serial devices, etc.) event notification or to associate timeout events with appropriate object instances and methods or functions. It is easy to use and no registration/deregistration/invocation code need to be written, because Qt's metaobject compiler (MOC) automatically generates the needed infrastructure.
A spreadsheet programs update system could be implemented using signals and slots such that when a cell is changed, its dependent cells are notified/updated.
using signalsandslots such that when a cell is changed, its dependent cells are notified/updated. There are some implementations of signal/slot systems...
football Signalsandslots, language construct used to simplify observer pattern implementations in signal programming and especially GUI design Slot (computer...
with Qt Designer are integrated with programmed code, using the Qt signalsandslots mechanism. Qt Quick Designer is a tool for developing animations by...
socket or CPU slot contains one or more mechanical components providing mechanical and electrical connections between a microprocessor and a printed circuit...
PCI Bus Request signalsand issue the Bus Grant Signals to the PCI slotsand to the PCI bridge chips (Bandit). The interrupt manager and logic board IO...
Railway semaphore signal is one of the earliest forms of fixed railway signals. This semaphore system involves signals that display their different indications...
Elements interact with each other and with the data graph to perform modeling and simulation tasks. A signalsandslots mechanism makes it possible for...
included progressively fewer PCI slots in favor of the new standard. Many new motherboards do not provide PCI slots at all, as of late 2013. [citation...
into 3.3 V slotsand vice versa, though "Universal" cards exist which will fit into either type of slot. There are also unkeyed "Universal" slots that will...
parses and executes SCXML state machines with a Lua data model. Qt SCXML Engine implemented in C++ as well and tightly integrated with their Signalsand Slots...
racing electric cars guided by center rails, and soon after, by slots in the track surface. The term "slot car" was coined to differentiate these from...
thick (i.e. 2.7 PCI slots at 20.32 mm), taking up 3 PCIe slots, while an Asus GeForce RTX 3080 video card takes up two slotsand measures 140.1 mm × 318...
unoccupied time slot or frequency band may be occupied by a signal inserted at the drop-and-insert point. Signals not of interest at the drop-and-insert point...
machine had bus expansion slots it would feature multiple bus expansions slots. However, there was never more than one PDS slot, as rather than providing...
A slotting fee, slotting allowance, pay-to-stay, or fixed trade spending is a fee charged to produce companies or manufacturers by supermarket distributors...
assembler language code. Modern processor designs generally do not use delay slots, and instead perform ever more complex forms of branch prediction to solve...
Standard ATX provides seven slots at 0.8 in (20 mm) spacing; the popular microATX size removes 2.4 inches (61 mm) and three slots, leaving four. Here width...
composite video signals, or other low-frequency applications requiring a shielded cable. RF connectors – are used to carry radio frequency signals between circuits...
The clock generator which produces the system clock signal to synchronize the various components Slots for expansion cards (the interface to the system via...
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